Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #93175

Re: Pure Python Data Mangling or Encrypting

Path csiph.com!usenet.pasdenom.info!news.albasani.net!feeder.erje.net!1.eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed8.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
Return-Path <python-python-list@m.gmane.org>
X-Original-To python-list@python.org
Delivered-To python-list@mail.python.org
X-Spam-Status OK 0.002
X-Spam-Evidence '*H*': 1.00; '*S*': 0.00; '16,': 0.03; 'subject:Python': 0.05; 'from:addr:yahoo.co.uk': 0.05; 'transform': 0.05; 'prefix': 0.07; 'bytes,': 0.09; 'cipher': 0.09; 'happen.': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'substitution': 0.09; '255': 0.16; 'cleartext': 0.16; 'duplicates': 0.16; 'encryption': 0.16; 'nope,': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'tables,': 0.16; 'utterly': 0.16; 'worst': 0.16; 'wrote:': 0.16; 'translation': 0.16; "wouldn't": 0.16; 'byte': 0.18; 'bytes': 0.18; 'duplicate': 0.18; 'network,': 0.18; 'language': 0.19; '>>>': 0.20; 'machine': 0.21; '(the': 0.22; 'do.': 0.22; 'fairly': 0.22; 'keys': 0.22; 'lawrence': 0.22; 'am,': 0.23; '2015': 0.23; 'tables': 0.23; 'header:In-Reply-To:1': 0.24; 'recognized': 0.24; 'header:User-Agent:1': 0.26; 'header:X-Complaints-To:1': 0.26; 'chris': 0.26; 'required.': 0.26; 'separate': 0.27; '[2]': 0.27; 'data,': 0.27; "doesn't": 0.28; 'figured': 0.29; 'lot.': 0.29; 'that.': 0.30; 'values': 0.30; 'work.': 0.30; 'becomes': 0.31; 'fri,': 0.31; 'seconds': 0.31; 'table': 0.32; 'computing': 0.32; 'language.': 0.32; 'file': 0.34; 'could': 0.35; 'to:addr:python- list': 0.35; 'attempt': 0.35; 'but': 0.36; 'being': 0.36; 'there': 0.36; 'possible': 0.36; "let's": 0.36; 'two': 0.37; 'subject:: ': 0.37; 'instead': 0.38; 'received:org': 0.38; 'say': 0.38; 'files': 0.38; 'end': 0.39; 'means': 0.39; 'to:addr:python.org': 0.39; 'easily': 0.39; 'data': 0.40; 'mark': 0.40; 'some': 0.40; 'even': 0.61; 'maximum': 0.61; 'simple': 0.61; 'times': 0.61; 'more': 0.62; 'our': 0.64; 'charset:windows-1252': 0.65; 'secure.': 0.66; 'subject:Data': 0.66; 'cut': 0.67; 'computers': 0.70; '26,': 0.72; 'sounds': 0.72; 'million': 0.73; 'attacking': 0.84; 'divide': 0.84; 'pythonistas,': 0.84; 'remained': 0.84; 'ridiculously': 0.84; 'start.': 0.84; 'maybe,': 0.91; 'received:2': 0.93; 'secrets': 0.93
X-Injected-Via-Gmane http://gmane.org/
To python-list@python.org
From Mark Lawrence <breamoreboy@yahoo.co.uk>
Subject Re: Pure Python Data Mangling or Encrypting
Date Fri, 26 Jun 2015 02:17:03 +0100
References <mmcagn$aa5$1@ger.gmane.org> <q67loadve6lsrh672u47omr04tvqttt6jd@4ax.com> <mailman.29.1435170987.3674.python-list@python.org> <558b7e85$0$1648$c3e8da3$5496439d@news.astraweb.com> <mailman.42.1435206516.3674.python-list@python.org> <558bc912$0$2899$c3e8da3$76491128@news.astraweb.com> <slrnmonkip.1nu.jon+usenet@frosty.unequivocal.co.uk> <558c1a7e$0$1668$c3e8da3$5496439d@news.astraweb.com> <slrnmoo7ev.1nu.jon+usenet@frosty.unequivocal.co.uk> <CAPTjJmqOzLTv9cFFKjV-BLtaFZhEZ4B870ALqNMmanCEN-VqXA@mail.gmail.com>
Mime-Version 1.0
Content-Type text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding 7bit
X-Gmane-NNTP-Posting-Host host-2-98-197-151.as13285.net
User-Agent Mozilla/5.0 (Windows NT 6.3; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0
In-Reply-To <CAPTjJmqOzLTv9cFFKjV-BLtaFZhEZ4B870ALqNMmanCEN-VqXA@mail.gmail.com>
X-BeenThere python-list@python.org
X-Mailman-Version 2.1.20+
Precedence list
List-Id General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe <https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive <http://mail.python.org/pipermail/python-list/>
List-Post <mailto:python-list@python.org>
List-Help <mailto:python-list-request@python.org?subject=help>
List-Subscribe <https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups comp.lang.python
Message-ID <mailman.91.1435281438.3674.python-list@python.org> (permalink)
Lines 44
NNTP-Posting-Host 2001:888:2000:d::a6
X-Trace 1435281438 news.xs4all.nl 2830 [2001:888:2000:d::a6]:45208
X-Complaints-To abuse@xs4all.nl
Xref csiph.com comp.lang.python:93175

Show key headers only | View raw

On 26/06/2015 01:33, Chris Angelico wrote:
> On Fri, Jun 26, 2015 at 1:26 AM, Jon Ribbens
> <jon+usenet@unequivocal.co.uk> wrote:
>>> There are only 256 possible values for n, one of which doesn't transform the
>>> data at all (ROT-0). If you're thinking of attacking this by pencil and
>>> paper, 255 transformations sounds like a lot. For a computer, that's barely
>>> harder than a single transformation.
>>
>> Well, it means you need to send 256 times as much data, which is a
>> start. If you're instead using a 256-byte translation table then
>> an attack becomes utterly impractical.
>>
>
> Utterly impractical? Maybe, if you attempt a pure brute-force approach
> - there are 256! possible translation tables, which is roughly e500
> attempts [1], and at roughly four a microsecond [2] that'd still take
> a ridiculously long time. But there are two gigantic optimizations you
> could do. Firstly, there are frequency-based attacks, and byte value
> duplicates will tell you a lot - classic cryptographic work. And
> secondly, you can simply take the first few bytes of a file - let's
> say 16, although a lot of files can be recognized in less than that.
> Even if there are no duplicate bytes, that'd be a maximum of 16!
> translation tables that truly matter, or just 2e13. At the same speed,
> that makes about a million seconds of computing time required. Divide
> that across a bunch of separate computers (the job is embarrassingly
> parallel after all), and you could get that result pretty easily. Cut
> the prefix to just 8 bytes and you have a mere 40K encryption keys to
> try - so quick that you wouldn't even see it happen. Nope, a simple
> substitution cipher is still not secure. Even the famous Enigma
> machine was a lot more than just letter-for-letter substitution - a
> double letter in the cleartext wouldn't be represented by a double
> letter in the result - and once the machine's secrets were figured
> out, the day's key could be reassembled fairly readily.
>

The day's key for a given network, with the Luftwaffe easily being the 
worst offenders.  Some networks remained unbroken at the end of WWII.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence

Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Re: Pure Python Data Mangling or Encrypting Randall Smith <randall@tnr.cc> - 2015-06-24 13:36 -0500
  Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve@pearwood.info> - 2015-06-25 14:07 +1000
    Re: Pure Python Data Mangling or Encrypting Devin Jeanpierre <jeanpierreda@gmail.com> - 2015-06-24 21:27 -0700
      Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-25 19:25 +1000
        Re: Pure Python Data Mangling or Encrypting Devin Jeanpierre <jeanpierreda@gmail.com> - 2015-06-25 02:41 -0700
        Re: Pure Python Data Mangling or Encrypting Chris Angelico <rosuav@gmail.com> - 2015-06-25 19:57 +1000
        Re: Pure Python Data Mangling or Encrypting Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-25 10:03 +0000
          Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve@pearwood.info> - 2015-06-26 01:13 +1000
            Re: Pure Python Data Mangling or Encrypting Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-25 15:26 +0000
              Re: Pure Python Data Mangling or Encrypting Randall Smith <randall@tnr.cc> - 2015-06-25 13:58 -0500
              Re: Pure Python Data Mangling or Encrypting Chris Angelico <rosuav@gmail.com> - 2015-06-26 10:33 +1000
                Re: Pure Python Data Mangling or Encrypting Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-26 10:49 +0000
              Re: Pure Python Data Mangling or Encrypting Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-25 19:01 -0600
                Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve@pearwood.info> - 2015-06-27 03:06 +1000
                Re: Pure Python Data Mangling or Encrypting Randall Smith <randall@tnr.cc> - 2015-06-26 15:09 -0500
                Re: Pure Python Data Mangling or Encrypting Johannes Bauer <dfnsonfsduifb@gmx.de> - 2015-06-26 23:07 +0200
                Re: Pure Python Data Mangling or Encrypting Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-26 21:29 +0000
                Re: Pure Python Data Mangling or Encrypting Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-26 22:55 +0100
                Re: Pure Python Data Mangling or Encrypting Johannes Bauer <dfnsonfsduifb@gmx.de> - 2015-06-27 00:42 +0200
                Re: Pure Python Data Mangling or Encrypting Devin Jeanpierre <jeanpierreda@gmail.com> - 2015-06-26 16:26 -0700
                Re: Pure Python Data Mangling or Encrypting Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-27 00:21 +0000
                Re: Pure Python Data Mangling or Encrypting Randall Smith <randall@tnr.cc> - 2015-06-26 19:55 -0500
                Re: Pure Python Data Mangling or Encrypting Johannes Bauer <dfnsonfsduifb@gmx.de> - 2015-06-27 07:24 +0200
                Re: Pure Python Data Mangling or Encrypting Randall Smith <randall@tnr.cc> - 2015-06-26 19:12 -0500
                Re: Pure Python Data Mangling or Encrypting Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-26 15:58 -0600
                Re: Pure Python Data Mangling or Encrypting Randall Smith <randall@tnr.cc> - 2015-06-26 19:23 -0500
                Re: Pure Python Data Mangling or Encrypting Johannes Bauer <dfnsonfsduifb@gmx.de> - 2015-06-26 23:11 +0200
                Re: Pure Python Data Mangling or Encrypting Michael Torrie <torriem@gmail.com> - 2015-06-27 11:02 -0600
                Re: Pure Python Data Mangling or Encrypting Paul Rubin <no.email@nospam.invalid> - 2015-06-27 10:45 -0700
                Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve@pearwood.info> - 2015-06-27 13:38 +1000
                Re: Pure Python Data Mangling or Encrypting Devin Jeanpierre <jeanpierreda@gmail.com> - 2015-06-26 21:05 -0700
                Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve@pearwood.info> - 2015-06-27 16:16 +1000
                Re: Pure Python Data Mangling or Encrypting Devin Jeanpierre <jeanpierreda@gmail.com> - 2015-06-27 13:30 -0700
                Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve@pearwood.info> - 2015-06-28 11:18 +1000
                Re: Pure Python Data Mangling or Encrypting Devin Jeanpierre <jeanpierreda@gmail.com> - 2015-06-27 19:11 -0700
                Re: Pure Python Data Mangling or Encrypting Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-26 23:47 -0600
                Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve@pearwood.info> - 2015-06-27 18:38 +1000
                Re: Pure Python Data Mangling or Encrypting Chris Angelico <rosuav@gmail.com> - 2015-06-27 18:53 +1000
                Re: Pure Python Data Mangling or Encrypting Johannes Bauer <dfnsonfsduifb@gmx.de> - 2015-06-27 11:07 +0200
                Re: Pure Python Data Mangling or Encrypting Chris Angelico <rosuav@gmail.com> - 2015-06-27 19:17 +1000
                Re: Pure Python Data Mangling or Encrypting Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-27 09:27 +0000
                Re: Pure Python Data Mangling or Encrypting Johannes Bauer <dfnsonfsduifb@gmx.de> - 2015-06-27 12:05 +0200
                Re: Pure Python Data Mangling or Encrypting Chris Angelico <rosuav@gmail.com> - 2015-06-27 20:16 +1000
                Re: Pure Python Data Mangling or Encrypting Johannes Bauer <dfnsonfsduifb@gmx.de> - 2015-06-27 12:55 +0200
                Re: Pure Python Data Mangling or Encrypting Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-27 10:26 +0000
                Re: Pure Python Data Mangling or Encrypting Laura Creighton <lac@openend.se> - 2015-06-27 14:27 +0200
                Re: Pure Python Data Mangling or Encrypting Johannes Bauer <dfnsonfsduifb@gmx.de> - 2015-06-27 12:18 +0200
                Re: Pure Python Data Mangling or Encrypting Chris Angelico <rosuav@gmail.com> - 2015-06-27 21:33 +1000
                Re: Pure Python Data Mangling or Encrypting Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-27 08:59 -0600
                Re: Pure Python Data Mangling or Encrypting Laura Creighton <lac@openend.se> - 2015-06-27 13:25 +0200
                Re: Pure Python Data Mangling or Encrypting Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2015-06-27 15:23 +0300
                Re: Pure Python Data Mangling or Encrypting Laura Creighton <lac@openend.se> - 2015-06-27 14:48 +0200
                Re: Pure Python Data Mangling or Encrypting Johannes Bauer <dfnsonfsduifb@gmx.de> - 2015-06-27 11:12 +0200
                Re: Pure Python Data Mangling or Encrypting Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-27 09:09 -0600
                Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve@pearwood.info> - 2015-06-28 03:35 +1000
                Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve@pearwood.info> - 2015-06-28 03:58 +1000
                Re: Pure Python Data Mangling or Encrypting Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-27 14:16 -0600
                Re: Pure Python Data Mangling or Encrypting Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-28 13:41 +0000
                Re: Pure Python Data Mangling or Encrypting Robert Kern <robert.kern@gmail.com> - 2015-06-27 08:58 +0100
                Re: Pure Python Data Mangling or Encrypting Robert Kern <robert.kern@gmail.com> - 2015-06-27 09:07 +0100
                Re: Pure Python Data Mangling or Encrypting Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-06-27 10:39 -0400
                Re: Pure Python Data Mangling or Encrypting Grant Edwards <invalid@invalid.invalid> - 2015-06-27 12:38 +0000
                Re: Pure Python Data Mangling or Encrypting Randall Smith <randall@tnr.cc> - 2015-06-27 13:22 -0500
                Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve@pearwood.info> - 2015-06-28 04:51 +1000
                Re: Pure Python Data Mangling or Encrypting Chris Angelico <rosuav@gmail.com> - 2015-06-28 09:05 +1000
                Re: Pure Python Data Mangling or Encrypting Chris Angelico <rosuav@gmail.com> - 2015-06-27 11:21 +1000
                Re: Pure Python Data Mangling or Encrypting Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-26 23:59 -0600
                Re: Pure Python Data Mangling or Encrypting Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-27 09:26 +0000
                Re: Pure Python Data Mangling or Encrypting Chris Angelico <rosuav@gmail.com> - 2015-06-27 16:52 +1000
                Re: Pure Python Data Mangling or Encrypting Randall Smith <randall@tnr.cc> - 2015-06-27 12:08 -0500
                Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve@pearwood.info> - 2015-06-28 04:50 +1000
                Re: Pure Python Data Mangling or Encrypting Randall Smith <randall@tnr.cc> - 2015-06-29 15:52 -0500
                Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve@pearwood.info> - 2015-06-30 13:00 +1000
                Re: Pure Python Data Mangling or Encrypting Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-30 12:19 +0000
                Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve@pearwood.info> - 2015-07-01 04:17 +1000
                Re: Pure Python Data Mangling or Encrypting Chris Angelico <rosuav@gmail.com> - 2015-07-01 04:33 +1000
                Re: Pure Python Data Mangling or Encrypting Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-30 18:37 +0000
                Re: Pure Python Data Mangling or Encrypting Randall Smith <randall@tnr.cc> - 2015-07-01 09:38 -0500
                Re: Pure Python Data Mangling or Encrypting Randall Smith <randall@tnr.cc> - 2015-06-30 12:39 -0500
                Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve@pearwood.info> - 2015-07-01 04:59 +1000
                Re: Pure Python Data Mangling or Encrypting Chris Angelico <rosuav@gmail.com> - 2015-07-01 05:20 +1000
                Re: Pure Python Data Mangling or Encrypting Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-30 23:25 +0000
                Re: Pure Python Data Mangling or Encrypting alister <alister.nospam.ware@ntlworld.com> - 2015-07-01 08:06 +0000
                Re: Pure Python Data Mangling or Encrypting Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-28 14:21 +0000
                Re: Pure Python Data Mangling or Encrypting Randall Smith <randall@tnr.cc> - 2015-06-29 15:46 -0500
                Re: Pure Python Data Mangling or Encrypting Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-29 20:49 +0000
                Re: Pure Python Data Mangling or Encrypting Randall Smith <randall@tnr.cc> - 2015-06-30 12:43 -0500
                Re: Pure Python Data Mangling or Encrypting Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-07-02 10:31 +1200
              Re: Pure Python Data Mangling or Encrypting Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-26 02:17 +0100
              Re: Pure Python Data Mangling or Encrypting Chris Angelico <rosuav@gmail.com> - 2015-06-26 12:06 +1000
              Re: Pure Python Data Mangling or Encrypting Chris Angelico <rosuav@gmail.com> - 2015-06-26 12:05 +1000
              Re: Pure Python Data Mangling or Encrypting Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-26 03:24 +0100
              Re: Pure Python Data Mangling or Encrypting Chris Angelico <rosuav@gmail.com> - 2015-06-26 12:29 +1000
        Re: Pure Python Data Mangling or Encrypting Joonas Liik <liik.joonas@gmail.com> - 2015-06-25 13:00 +0300
        Re: Pure Python Data Mangling or Encrypting Devin Jeanpierre <jeanpierreda@gmail.com> - 2015-06-25 03:18 -0700
    Re: Pure Python Data Mangling or Encrypting Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-25 17:05 +1000
    Re: Pure Python Data Mangling or Encrypting Randall Smith <randall@tnr.cc> - 2015-06-25 14:09 -0500

csiph-web